GI Disease Flashcards
How do you diagnose acute pancreatitis?
For diagnosis of acute pancreatitis, need 2 of 3:
– Abdominal pain characteristic of disease
– Amylase and/or lipase elevated at least 3x upper limit of normal (ULN)
– Characteristic imaging findings
Why is lipase (compared to amylase) often preferred in diagnosing pancreatitis?
• Lipase is preferred: more sensitive and
more specific for acute pancreatitis
• Neither enzyme has accepted prognostic value
• Lipase remains elevated longer than amylase
• Current recommendations are for lipase measurement alone.
How does sensitivity/specifity compare for diagnosis of pancreatitis w/ lipase and amylase?
Lipase: 90/93
Amylase: 78/92
What else besides acute pancreatitis can cause elevations in pancreatic enzymes?
- Macroamylasemia/macrolipasemia
- Renal failure
- Acute appendicitis
- Cholecystitis
- Intestinal ischemia or obstruction
- Peptic ulcer disease
- Gynecological disease
- Diabetes (higher lipase, so diagnostic cutoff is >3-5 ULN, but no consensus on actual value)
- Parotid/salivary gland disease (amylase only)
What are causes of acute pancreatitis?
- Gallstones and alcohol are most common
- Hypercalcemia, hypertriglyceridemia
- Post-ERCP, trauma/injury
- Genetic pancreatitis(e.g.,CFmutations)
- Drugs (e.g., azathioprine, sulfonamides, NSAIDs, steroid, tetracycline)
- Viral infections (e.g., mumps, rubella, EBV, CMV, hepatitis)
bruising around umbiliccus
cullens
bruising around spleen/flank
greys
What are first tier LFTs?
• Transaminases – ALT, AST • Bilirubin • Alkaline phosphatase, γ-glutamyl transferase (GGT) • Albumin • Prothrombin time/INR
What are second tier LFTs?
• Hepatitis viral serologies and molecular tests • Fe, ferritin, Cu • Alpha-1 antitrypsin • Autoantibody tests
What are the three classifiaitons of liver disease?
- hepatocellular injury/necrosis (damage/death to hepatocytes)
ALT,AST > AP - Cholestatic (obstruction of bile outflow from liver)
AP > ALT or AST - Infiltrative (neoplasm, amyloid)
elevated AP w/ normal ALT, AST or AP > ALT, AST
What are transaminases and how do they differ?
• ALanine aminotransferase (ALT) (SGPT)
• ASpartate aminotransferase (AST) (SGOT)
• These “leak” from damaged hepatocytes
• ALT is more SPECIFIC for LIVER disease
– AST is found in MUSCLE and RED
– With extensive muscle breakdown, both ALT and AST rise
• ALT has a LONGER half-life
Where does AP come from?
• Present on hepatocyte membrane bordering the bile canaliculi • Isoenzymes: liver, bone, placenta – Elevation is not a specific marker for liver disease • Bone, GI, kidney
When would you order GGT?
to confirm a liver source
What are reference intervals for AST/ALT?
• AST 0-45 U/L, female; 0-55 U/L, male
– Children higher to age 2
• ALT 0-50 U/L, female; 0-70 U/L, male
What are reference intervals for AP?
• Alkaline phosphatase 40-150 U/L
What are markers of liver function?
• Albumin
– Half-life of 21 days, but can fall more rapidly with severe inflammation
– Can fall with renal or GI losses, or burns
• Prothrombin time (PT, INR)
What causes an acute rise in transaminases?
HepA/B Drug induced hepatitis Alcoholic Ischemic (shock liver) Acute duct obstruction Wilson disease Autoimmune hepatitis
Diagnostic test: Hep A
IgM anti-HAV
Diagnostic test: Hep B
HBsAg, IgM angti-HBc
Diagnostic test: drug induced hepatitis
improvement on stopping
Diagnostic test: alcoholic
liver bx
improvement iwth abstinence
AST:ALT >2
AST <400
Diagnostic test: shock liver
improvement iwth restoration of circulation
Diagnostic test: acute duct obstruction
cholangiography
Diagnostic test: wilson disease
ceruloplasmin
urine copper
slit lamp
liver Cu measurement
Diagnostic test: autoimmune hepatitis
anti-smooth muscle (f actin)
anti-LKM type 1
How high can ALTL be with acute hepatitis?
thousands
If ALT over 5000 consider….
acetaminophen
hepatic ischemia
unusual viruses like HSV
stones can cause transient elevations to…
1000s